Technical Field
This application generally relates to data storage, and more particularly to techniques used in connection with determining and performing data movements in a multi-tiered storage environment.
Description of Related Art
Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage devices such as those included in the data storage systems manufactured by EMC Corporation. These data storage systems may be coupled to one or more host processors and provide storage services to each host processor. Multiple data storage systems from one or more different vendors may be connected and may provide common data storage for one or more host processors in a computer system.
A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests, such as data read and write operations.
Host processor systems may store and retrieve data using a storage system containing a plurality of host interface units, disk drives, and disk interface units. Such storage systems are provided, for example, by EMC Corporation of Hopkinton, Mass. The host systems access the storage system through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage system and the storage system provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage system directly, but rather, access what appears to the host systems as a plurality of logical disk units, logical devices, or logical volumes (LVs). The logical disk units may or may not correspond to the actual disk drives. Allowing multiple host systems to access the storage system allows the host systems to share data stored therein.
In connection with data storage, a host may issue I/O operations to copy data from a source location on a source device to a target location on a target device. The source and target devices may be on the same or different data storage systems. To perform the operation, the host may issue a read command to read the data to be copied from the source location of the source device from a source data storage system. In response, the source data storage system may send the requested data across a network connection to the host. The host may then issue a write command to a target data storage system including the target device. For the write operation, the host transmits the data to the target data storage system whereby the target data storage system writes the data to the target location of the target device.